CN108344702B - Method for measuring sulfur dioxide content in vanadium energy storage medium by ultraviolet visible spectrophotometry - Google Patents
Method for measuring sulfur dioxide content in vanadium energy storage medium by ultraviolet visible spectrophotometry Download PDFInfo
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Abstract
The invention provides a method for determining sulfur dioxide content in a vanadium energy storage medium by an ultraviolet visible spectrophotometry, which comprises the steps of distilling sulfur dioxide existing in a sample solution in a sulfite form and feeding the sulfur dioxide into an absorption liquid containing a lead acetate fixing agent in a distillation mode, and improving the absorption efficiency of the sulfur dioxide by utilizing the formation of lead sulfite precipitates; adding quantitative iodine solution into the absorption liquid, and measuring the content of iodine and sulfite through ultraviolet-visible spectrophotometer
And (5) analyzing and calculating the sulfur dioxide content in the sample solution according to the change of the light absorption intensity at the characteristic spectrum. The method has high detection sensitivity and has very wide application prospect in the quality control detection of the vanadium energy storage medium.
Description
Technical Field
The invention relates to a material measurement technology, in particular to a method for measuring sulfur dioxide content in a vanadium energy storage medium by an ultraviolet visible spectrophotometry.
Background
Vanadium batteries are widely applied to the field of new energy sources in recent years as a new energy storage battery. The vanadium energy storage medium is a main component of the vanadium battery. Among them, the sulfuric acid system vanadium energy storage medium is most widely applied in vanadium batteries. Concentrated sulfuric acid is one of important auxiliary materials applied in the production of vanadium energy storage media, and contains sulfur dioxide with different contents. During the operation of the vanadium battery, along with the reduction reaction of vanadium, sulfur dioxide existing in the cathode in the form of sulfite is reduced into hydrogen sulfide, insoluble metal sulfide and the like. Wherein, hydrogen sulfide is extremely volatile and can cause harm to surrounding personnel and environment when being volatilized into air; the insoluble metal sulfide can seriously affect the stability and the energy storage efficiency of the vanadium energy storage medium. Therefore, the content of sulfur dioxide in the vanadium energy storage medium is accurately detected and controlled, and the method has important significance for quality control of the vanadium energy storage medium.
The vanadium energy storage medium of the sulfuric acid system contains high-concentration sulfate radicals and vanadium ions, wherein the vanadium concentration and the sulfate radical concentration are as high as more than 2mol/L and 4mol/L, and the sulfur dioxide content in the vanadium energy storage medium needs to be controlled below 5 mg/L. The detection of sulfur dioxide in vanadium energy storage media faces several difficulties: 1) the detection sensitivity requirement is high; 2) the high-concentration vanadium enables the vanadium energy storage medium to have a darker color; 3) high-concentration sulfate radicals, and partial sulfuric acid is distilled out to enter absorption liquid in the high-temperature distillation process. Therefore, the current literature reports that the distillation-absorption oxidation-ion chromatography is adopted to measure the sulfur radicals in the absorption liquid for sulfur dioxide detection, and the distillation-absorption-titration method in pharmacopoeia cannot meet the requirement of vanadium energy storage medium on the detection sensitivity of the sulfur dioxide content.
Therefore, a method for measuring sulfur dioxide in a vanadium energy storage medium with higher detection sensitivity is urgently needed.
Disclosure of Invention
The invention aims to provide a method for measuring the content of sulfur dioxide in a vanadium energy storage medium by using an ultraviolet-visible spectrophotometry, which has high detection sensitivity, can be beneficial to effectively controlling the content of sulfur dioxide in the vanadium energy storage medium in the production process and has very wide application prospect in the quality control and detection of the vanadium energy storage medium, aiming at the problems that the detection sensitivity of the content of sulfur dioxide in the energy storage medium is low and the control of the content of sulfur dioxide in the vanadium energy storage medium in the production process cannot be realized.
In order to achieve the purpose, the invention adopts the technical scheme that: a method for measuring the content of sulfur dioxide in a vanadium energy storage medium by an ultraviolet-visible spectrophotometry comprises the following steps:
step 1) standard working curve making
Transferring the series of volumes of sodium sulfite standard solutions into N brown containers filled with lead acetate solutions, respectively adding iodine saturated solutions into the N brown containers, and uniformly mixing, wherein N is more than or equal to 5; after reacting for 2-5min, adding a proper amount of concentrated hydrochloric acid to dissolve lead sulfate precipitate obtained by oxidizing lead sulfite and eliminate the influence of the precipitate on ultraviolet spectrophotometry detection; adding water to desired volume to obtain N samples, standing for 3-5min, and performing ultraviolet and visible light irradiationMeasuring the solution absorbance values of the N samples to be measured at the characteristic spectral wavelength by a spectrophotometer, wherein the characteristic spectral wavelength is 287nm or 350nm, and SO contained in the series volume sodium sulfite standard solution2The content (mg) of (A) is taken as a horizontal coordinate, and a standard working curve is drawn by taking the absorbance as a vertical coordinate to obtain a linear relation between the mass (mg) of the sulfur dioxide and the absorbance A; the volume ratio of the lead acetate solution to the iodine saturated solution is 1: 2-4;
step 2) determination of sulfur dioxide content in vanadium energy storage medium
Absorbing sulfur dioxide gas distilled from the vanadium energy storage medium by using a lead acetate solution; after distillation is carried out for 20-40min, adding iodine saturated solution into the lead acetate solution absorbing sulfur dioxide, and leading into a brown container after full reaction; adding a proper amount of concentrated hydrochloric acid into a brown container to dissolve lead sulfate precipitate obtained by oxidizing lead sulfite, eliminating the influence of the precipitate on ultraviolet spectrophotometry detection, and performing volume fixing with water to obtain a sample to be detected; standing the sample to be tested for 3-5min, sampling, and measuring the absorbance value of the sample to be tested at 287nm by using an ultraviolet-visible spectrophotometer; substituting the absorbance value into a linear equation of a standard working curve to calculate the mass of sulfur dioxide, and dividing the value by the sampling volume to obtain the content (mg/L) of sulfur dioxide in the sample solution; the volume ratio of the lead acetate solution to the iodine saturated solution in the step 2) is the same as that in the step 1). And the concentration of the lead acetate solution in the step 2) is the same as that of the lead acetate solution in the step 1).
Further) the concentration of the lead acetate solution is 1-2g/L, and the lead acetate solution is absorption liquid of sulfur dioxide.
Further, the preparation steps of the iodine saturated solution are as follows: weighing iodine solid (accurate to 0.00001g), dissolving in anhydrous ethanol container, stirring to dissolve iodine completely, pouring iodine ethanol solution into brown container containing tertiary water, dissolving with ultrasound, and standing for one day; filtering to obtain clear and transparent iodine solution; wherein the ratio of the mass of the iodine solid to the volume of the absolute ethyl alcohol to the volume of the tertiary water is 1-2 g: 10-20 mL: 1L of the compound.
Further, the validity period of the standard working curve in the step 1) is 3 days, and the standard working curve needs to be made again when the iodine saturated solution is replaced.
Further, the characteristic spectral wavelength of the solution in the step 1) is 287 nm.
Further, the volume ratio of the concentrated hydrochloric acid and the lead acetate solution added in the step 1) or the step 2) is 1:50-100, so that the lead sulfate precipitate obtained by oxidizing the lead sulfite is dissolved, and the influence of the precipitate on the ultraviolet spectrophotometry detection is eliminated.
Further, in the step 2), the distillation temperature is 120-160 ℃, preferably the distillation temperature is 140 ℃, and the distillation time is 20-40 min.
Further, the method for absorbing the distilled sulfur dioxide gas by using the lead acetate solution comprises the following steps: introducing argon into an absorption container added with a lead acetate solution, injecting a vanadium energy storage medium (by using an injector) into a distillation container at the argon flow rate of 150-. By controlling the sampling volume of the vanadium energy storage medium, the total amount of sulfur dioxide in the distillation bottle is not more than 0.3mg, and the total volume of the vanadium energy storage medium and the added tertiary water in the distillation container is 120-130 mL. The volume ratio of the lead acetate solution to the tertiary water is as follows: 10: 60
The invention relates to a method for measuring sulfur dioxide content in a vanadium energy storage medium by an ultraviolet visible spectrophotometry, which adopts a distillation mode to distill off sulfur dioxide existing in a sulfite form in a sample solution and feed the sulfur dioxide into an absorption liquid containing a lead acetate fixing agent, and improves the absorption efficiency of the sulfur dioxide by utilizing the formation of lead sulfite precipitates; adding quantitative iodine solution into the absorption liquid, and measuring I generated by quantitative redox reaction of iodine and sulfite by using an ultraviolet-visible spectrophotometer3 -And (5) analyzing the sulfur dioxide content in the sample solution by the change of the light absorption intensity at the characteristic spectrum. Specifically, the present invention has the following advantages compared to the prior art:
1) the invention takes lead acetate solution as absorption liquid, thus improving the absorption efficiency of sulfur dioxide in the distillation process; the iodine added into the absorption liquid is converted into iodine by utilizing the reducibility of sulfur dioxide
Ions, utilization of
Absorption characteristic pair of ions
And carrying out quantitative analysis on the ions, and calculating the mass of the sulfur dioxide by utilizing the quantitative reaction between the iodine and the sulfur dioxide so as to obtain the content of the sulfur dioxide in the vanadium energy storage medium.
2) The invention adopts the redox reaction detection and determination method, thereby avoiding the influence of sulfate radical on the detection result in the process of detecting sulfur dioxide by ion chromatography.
3) The method has higher detection sensitivity, can accurately detect the sulfur dioxide with the content lower than 0.5mg/L in the vanadium energy storage medium, and is suitable for detecting the sulfur dioxide concentration in the production debugging process and the product quality control process of the vanadium energy storage medium.
Drawings
FIG. 1 is a schematic view of a distillation-absorption apparatus;
FIG. 2 is a schematic view of the structure of an absorber tube;
FIG. 3 is a scan pattern of a reagent interference assay; wherein the graph a is as follows:
(0.2 mmol/L); panel b includes: h2O，Pb(CH3COO)2(0.6mmol/L)，Na2SO3(0.03mmol/L)，I2(0.2mmol/L)，KI(0.3mmol/L),HCl(24mmol/L)
FIG. 4 is a wavelength scan of a standard solution UV-Vis spectrophotometer (where SO)2：0mg、0.03mg、0.06mg、0.12mg、0.24mg、0.36mg)；
FIG. 5 is a standard operating curve at a wavelength of 287nm (where SO2：0mg、0.03mg、0.06mg、0.12mg、0.24mg、0.36mg)；
FIG. 6 is a standard operating curve at a wavelength of 350nm (where SO2：0mg、0.03mg、0.06mg、0.12mg、0.24mg、0.36mg)。
Detailed Description
The invention discloses a sulfur dioxide content method with a very wide application prospect in quality control detection of a vanadium energy storage medium, which comprises the following steps: a method for measuring the content of sulfur dioxide in a vanadium energy storage medium by an ultraviolet visible spectrophotometry. The method comprises the following steps: 1) solution preparation: iodine saturated solution, lead acetate absorption liquid and sodium sulfite standard solution (series volume sodium sulfite standard solution); 2) making a standard working curve; 3) distilling and absorbing sulfur dioxide; 4) oxidation-reduction reaction between iodine and lead sulfite in the absorption liquid; 5) and (5) colorimetric and calculation.
The method comprises the following specific steps:
1) solution preparation:
preparation of lead acetate solution: 4.0g of anhydrous lead acetate (accurate to 0.1g) is accurately weighed and dissolved in a reagent bottle filled with 2L of tertiary water, and the solution is clarified and transparent by ultrasonic dissolution.
Preparation of iodine saturated solution: 3.00000g of iodine solid (accurate to 0.00001g) is accurately weighed and dissolved in a beaker filled with 30mL of absolute ethanol, the iodine is fully dissolved by stirring with a glass rod, and then the ethanol solution of the iodine is poured into a brown bottle filled with 3L of tertiary water, dissolved by ultrasound and placed for one day. After one day, filtration using filter paper gave a clear and transparent iodine saturated solution.
Preparation of sodium sulfite standard solution: accurately weighing anhydrous Na2SO30.10000g of solid (accurate to 0.00001g) is dissolved in 100mL of tertiary water, shaken, sonicated and shaken up.
2) And (3) preparing a standard curve:
respectively transferring 10.00mL of the prepared lead acetate solution into 6 brown volumetric flasks of 100 mL; respectively transferring 0mL, 0.05mL, 0.1mL, 0.2mL, 0.4mL and 0.6mL of the prepared sodium sulfite standard solution into 6 brown volumetric flasks of 100mL by using a liquid transfer gun; accurately transferring 20.00mL of the prepared iodine saturated solution into 6 brown volumetric flasks of 100 mL; respectively adding 200 mu L of concentrated hydrochloric acid; the volume is determined to be 100mL by water, the mixture is shaken and shaken up, and 6 samples are respectively stabilized for 5 min. After 5min, the reaction was carried out at 287nm using a 1cm quartz cuvetteLine detection; conversion of sodium sulfite solution to SO2The absorbance and SO are given by plotting a standard curve with the content (in mg) of (A) as abscissa and the absorbance as ordinate2And (4) a calculation formula for mutual calculation between contents. A ═ bx + a (where a: absorbance value; b: reticle slope; a: linear intercept).
3) Distillation absorption of sulfur dioxide
The distillation device is assembled from right to left, 10mL of the prepared lead acetate solution is added into the receiving tube, the argon switch is opened, the argon flow is adjusted to 200mL/min at a speed of SO2Taking 60mL (by using an injector) of vanadium energy storage medium into a 250mL two-neck flask for a sample with the content of below 5mg/L, measuring 70mL of tertiary water by using a measuring cylinder, adding the tertiary water into the two-neck flask from an acid adding nitrogen introducing tube (or a bubbling tube), and bubbling for 10 min. After the bubbling is finished, lifting the lifting platform to enable the distillation flask to be placed in an oil bath pan with the temperature of 140 ℃ (the surface of the oil bath is covered by a paperboard in the heating process), and heating at constant temperature for 20 min.
4) Color reaction
After distillation is finished, adding 20.00mL of iodine saturated solution into a receiving tube, transferring the solution into a 100mL brown volumetric flask after full reaction, washing the receiving tube with three-level water until the solution is completely transferred, adding 200 mu L of concentrated hydrochloric acid, fixing the volume to 100mL, and standing for 5 min;
5) and (3) measuring the absorbance value of a sample at 287nm by using a 1cm quartz cuvette and applying an ultraviolet-visible spectrophotometer, substituting the absorbance value into a standard working curve linear equation to calculate the mass of sulfur dioxide, and then dividing the mass by the sampling volume to obtain the content (mg/L) of sulfur dioxide in the vanadium energy storage medium.
The reaction equations that occur in the present invention include: the sulfur dioxide enters absorption liquid and lead ions to generate lead sulfite sediment in the formula (1);
formula (2) carrying out oxidation-reduction reaction on iodine and lead sulfite to generate lead sulfate precipitate;
formula (3) the form of iodide ion;
formula (4) dissolution reaction of lead sulfate precipitate;
(1)Pb2++SO2+H2O＝PbSO3↓+2H+
(2)PbSO3↓+I2+H2O＝PbSO4↓+2H++2I-
(3)
(4)PbSO4↓+4Cl-＝PbCl4 2-+SO4 2-
in the method, only the reagent which is confirmed to be analytically pure and the water which meets the requirements of the third-level water in GB/T6682 'water specification and test method for analytical laboratories' are used.
The invention is further illustrated by the following examples:
example 1 interference wavelength scanning patterns of standard solutions and reagents
1. Preparation of lead acetate Vinegar solution (Pb (CH)3COO)2(0.6mmol/L))
1A, accurately weighing 4.0g (accurate to 0.1g) of analytically pure anhydrous lead acetate, dissolving the anhydrous lead acetate in a reagent bottle filled with 2L of tertiary water, and ultrasonically dissolving to ensure that the solution is clear and transparent.
1B, transferring 10.00mL of the prepared lead acetate solution into a 100mL brown volumetric flask, and fixing the volume;
2. preparation of iodine solution I2(0.2mmol/L)
2A, accurately weighing 3.00000g (accurate to 0.00001g) of analytically pure iodine solid, dissolving the solid in a beaker filled with 30mL of absolute ethyl alcohol, stirring the solution by a glass rod to fully dissolve the iodine, then pouring the ethanol solution of the iodine into a brown reagent bottle filled with 3L of tertiary water, ultrasonically dissolving the solution, and standing the solution for one day. After one day, filtration using filter paper gave a clear and transparent iodine saturated solution.
2B, transferring 5.00mL of the prepared iodine saturated solution into a 100mL brown volumetric flask, and fixing the volume;
3. preparation of potassium iodide solution KI (0.3mmol/L),
3A, 3.00000g of potassium iodide solid (accurate to 0.00001g) was accurately weighed and analyzed, dissolved in a brown reagent bottle containing 3L of tertiary water, and ultrasonically dissolved.
3B, transferring 5.00mL of the prepared iodine dramatic solution into a 100mL brown volumetric flask, and fixing the volume;
4. preparation of sodium sulfite Standard solution Na2SO3(0.03mmol/L)
4A, accurately weighing reference anhydrous Na2SO30.10000g of solid (accurate to 0.00001g) is dissolved in 100mL of tertiary water, shaken, sonicated and shaken up.
4B, using a liquid transfer gun to transfer 0.4mL of the prepared sodium sulfite standard solution into a 100mL brown volumetric flask, and fixing the volume;
5、I3 -preparation of the solution I3 -(0.2mmol/L)
5A, accurately weighing 3.00000g (accurate to 0.00001g) of analytically pure iodine solid, dissolving the solid in a beaker filled with 30mL of absolute ethyl alcohol, stirring the solution by a glass rod to fully dissolve the iodine, then pouring the ethanol solution of the iodine into a brown reagent bottle filled with 3L of tertiary water, ultrasonically dissolving the solution, and standing the solution for one day. After one day, filtration using filter paper gave a clear and transparent iodine saturated solution.
5B, accurately weighing 3.00000g (accurate to 0.00001g) of potassium iodide solid, dissolving in a brown reagent bottle containing 3L of tertiary water, and ultrasonically dissolving.
5C, respectively transferring 5.00mL of the prepared iodine saturated solution and potassium iodide solution into a 100mL brown volumetric flask, fixing the volume, and fully and uniformly mixing;
6. preparation of hydrochloric acid solution HCl (24mmol/L)
6A, transferring 200 mu L of concentrated hydrochloric acid into a 100mL brown volumetric flask by using a liquid transfer gun, and fixing the volume;
7. reagent interference analysis scanning
The prepared 6 solutions (Pb (CH) were measured using a Lambda35 UV-visible spectrophotometer manufactured by PE corporation and a 1cm quartz cuvette3COO)2(0.6mmol/L),Na2SO3(0.03mmol/L),I2(0.2mmol/L),KI(0.3mmol/L),HCl(24mmol/L),I3 -(0.2mmol/L)) and water at 250nm-450nm to obtain a scanning spectrum of reagent interference analysis, and the result is shown in FIG. 3.
8. Standard analysis scan
8A, respectively transferring 10.00mL of the prepared lead acetate solution into 6 brown volumetric flasks of 100 mL;
8B, respectively transferring 0mL, 0.05mL, 0.1mL, 0.2mL, 0.4mL and 0.6mL of the prepared sodium sulfite standard solution into 6 brown volumetric flasks of 100mL by using a liquid transfer gun;
8C, accurately transferring 20.00mL of the prepared iodine saturated solution into 6 brown volumetric flasks with 100 mL;
8D, respectively adding 200 mu L of concentrated hydrochloric acid;
and 8E, diluting to 100mL with water, oscillating, shaking up, and stabilizing 6 samples for 5min respectively. 8F, performing spectrum scanning on the prepared 6 standard solutions by using a Lambda35 ultraviolet-visible spectrophotometer and a 1cm quartz cuvette manufactured by PE company to obtain analysis scanning spectrums of the standard solutions with series concentrations, wherein the analysis scanning spectrums are shown in figure 4; the absorption intensities at 287nm and 350nm were read, respectively, and the concentration of the standard solution was plotted on the abscissa and the corresponding absorption intensity was plotted on the ordinate to obtain FIGS. 5 and 6.
Example 2
1. Preparation of lead acetate solution
4.0g (accurate to 0.1g) of analytically pure anhydrous lead acetate is accurately weighed and dissolved in a reagent bottle filled with 2L of tertiary water, and the solution is clarified and transparent by ultrasonic dissolution.
2. Preparation of iodine-saturated solution
3.00000g of analytically pure iodine solid (accurate to 0.00001g) was accurately weighed, dissolved in a beaker containing 30mL of absolute ethanol, stirred with a glass rod to fully dissolve iodine, and then the ethanol solution of iodine was poured into a brown reagent bottle containing 3L of tertiary water, dissolved by ultrasound, and left to stand for one day. After one day, filtration using filter paper gave a clear and transparent iodine saturated solution.
3. Preparation of sodium sulfite Standard solution
Accurately weighing reference anhydrous Na2SO30.10000g of solid (accurate to 0.00001g) is dissolved in 100mL of tertiary water, shaken, sonicated and shaken up.
4. And (3) preparing a standard curve:
4A, respectively transferring 10.00mL of the prepared lead acetate solution into 6 brown volumetric flasks with 100 mL;
4B, respectively transferring 0mL, 0.05mL, 0.1mL, 0.2mL, 0.4mL and 0.6mL of the prepared sodium sulfite standard solution into 6 brown volumetric flasks of 100mL by using a liquid transfer gun;
4C, accurately transferring 20.00mL of the prepared iodine saturated solution into 6 brown volumetric flasks with 100 mL;
4D, respectively adding 200 mu L of concentrated hydrochloric acid;
and 4E, diluting to 100mL with water, oscillating, shaking up, and stabilizing 6 samples for 5min respectively. After 5min, detection was carried out at 287nm using a 1cm quartz cuvette.
4F, converting sodium sulfite standard solution into SO2The absorbance and SO are given by plotting a standard curve with the content (in mg/L) of (A) as abscissa and the absorbance as ordinate2And (4) a calculation formula for mutual calculation between contents.
A＝bx+a
5. Sample detection
5A, a distillation device is adopted as shown in figures 1-2, wherein 1 is an absorption tube; 2. a 105-degree elbow; 3. a condenser tube; 4. a 75-degree elbow; 5. a distillation flask; 6. adding acid and introducing into a nitrogen tube. Firstly, fixing a distillation flask 5, inserting an acid adding nitrogen introducing pipe 6 at the pipe orifice of a measuring pipe on the right side of the distillation flask 5, connecting the inlet of the acid adding nitrogen introducing pipe 6 with an argon bottle through a hose, connecting a 75-degree elbow 4 at the outlet of the upper end of the distillation flask, and then sequentially connecting the inlet of a condenser pipe, the outlet of the condenser pipe, a 105-degree elbow and an absorption pipe;
assembling the distillation device from right to left to SO2Adding 10mL of the prepared lead acetate solution into a receiving tube, opening an argon switch, and rapidly adjusting the flow rate of argon to 200mL/min for SO2Taking 60mL (by using an injector) of vanadium energy storage medium into a 250mL two-neck flask for a sample with the content of below 5mg/L, measuring 70mL of tertiary water by using a measuring cylinder, adding the tertiary water into the two-neck flask from an acid adding nitrogen introducing tube (or a bubbling tube), and bubbling for 10 min. After the bubbling is finished, lifting the lifting platform to enable the distillation flask to be placed in an oil bath pan with the temperature of 140 DEG C(in the heating process, the oil bath surface is covered with a paperboard), and the mixture is heated at constant temperature for 20 min. After the distillation is finished, the mixture is fed to SO2After 20.00mL of the iodine-saturated solution was added to the receiving tube, the whole volume was transferred to a 100mL brown volumetric flask, and 200. mu.L of concentrated hydrochloric acid was added to the brown volumetric flask to fix the volume. After 5min, detection was carried out at 287nm using a 1cm quartz cuvette.
5B, calculating
Calculating SO in sodium sulfite standard solution according to formula (1)2The unit of the content of (A) is mg/L;
in the formula: m represents the weighing sample amount of sodium sulfite, and the unit is g;
v, preparing the volume of a sodium sulfite standard solution, wherein the unit is mL;
64—SO2a molecular weight;
126—Na2SO3a molecular weight;
1000-ml and liter conversion factor;
calculating SO in the sample according to the formula (2)2The content is mg/L;
in the formula: a-absorbance of the sample solution;
b-extinction coefficient;
a-intercept;
V1reacting the absorption liquid to a constant volume, wherein the unit is mL;
V0volume of sample stock solution in mL.
5C, according to the operation steps, a vanadium energy storage medium sample A (V: 1.64mol/L, V)3+：0.83mol/L、SO4 2-: 4.11mol/L) is sampled for detection by 60mL, the absorbance is 0.246, and the SO in the sample2The contents are as follows:
example 3
1. Preparation of lead acetate solution
4.0g (accurate to 0.1g) of analytically pure anhydrous lead acetate is accurately weighed and dissolved in a reagent bottle filled with 2L of tertiary water, and the solution is clarified and transparent by ultrasonic dissolution.
2. Preparation of iodine-saturated solution
3.00000g of analytically pure iodine solid (accurate to 0.00001g) was accurately weighed, dissolved in a beaker containing 30mL of absolute ethanol, stirred with a glass rod to fully dissolve iodine, and then the ethanol solution of iodine was poured into a brown reagent bottle containing 3L of tertiary water, dissolved by ultrasound, and left to stand for one day. After one day, filtration using filter paper gave a clear and transparent iodine saturated solution.
3. Preparation of sodium sulfite Standard solution
Accurately weighing reference anhydrous Na2SO30.10000g of solid (accurate to 0.00001g) is dissolved in 100mL of tertiary water, shaken, sonicated and shaken up.
4. And (3) preparing a standard curve:
4A, respectively transferring 10.00mL of the prepared lead acetate solution into 6 brown volumetric flasks with 100 mL;
4B, respectively transferring 0mL, 0.05mL, 0.1mL, 0.2mL, 0.4mL and 0.6mL of the prepared sodium sulfite standard solution into 6 brown volumetric flasks of 100mL by using a liquid transfer gun;
4C, accurately transferring 20.00mL of the prepared iodine solution into 6 brown volumetric flasks with 100 mL;
4D, respectively adding 200 mu L of concentrated hydrochloric acid;
and 4E, diluting to 100mL with water, oscillating, shaking up, and stabilizing 6 samples for 5min respectively. After 5min, detection was carried out at 287nm using a 1cm quartz cuvette.
4F, converting sodium sulfite standard solution into SO2The absorbance and SO are given by plotting a standard curve with the content (in mg/mL) of (A) as the abscissa and the absorbance as the ordinate2The contents are mutually combinedAnd (4) calculating a calculation formula.
A＝bx+a
5. Sample detection
5A, assembling the distillation device from right to left and then feeding the distillation device to SO2Adding 10mL of the prepared lead acetate solution into a receiving tube, opening an argon switch, and rapidly adjusting the flow rate of argon to 200mL/min for SO2Taking 30mL (by using an injector) of vanadium energy storage medium into a 250mL two-neck flask for a sample with the content of 5-10mg/L, measuring 70mL of tertiary water by using a measuring cylinder, adding the tertiary water into the two-neck flask from an acid adding nitrogen introducing tube (or a bubbling tube), and bubbling for 10 min. After the bubbling is finished, lifting the lifting platform to enable the distillation flask to be placed in an oil bath pan with the temperature of 140 ℃ (the surface of the oil bath is covered by a paperboard in the heating process), and heating at constant temperature for 20 min. After the distillation is finished, the mixture is fed to SO2After 20.00mL of the iodine-saturated solution was added to the receiving tube, the whole volume was transferred to a 100mL brown volumetric flask, and 200. mu.L of concentrated hydrochloric acid was added to the brown volumetric flask to fix the volume. After 5min, detection was carried out at 287nm using a 1cm quartz cuvette.
5B, calculating
Calculating SO in sodium sulfite standard solution according to formula (1)2The unit of the content of (A) is mg/L;
in the formula: m represents the weighing sample amount of sodium sulfite, and the unit is g;
v, preparing the volume of a sodium sulfite standard solution, wherein the unit is mL;
64—SO2a molecular weight;
126—Na2SO3a molecular weight;
1000-ml and liter conversion factor;
calculating SO in the sample according to the formula (2)2The content is mg/L;
in the formula: a-absorbance of the sample solution;
b-extinction coefficient;
a-intercept;
V1reacting the absorption liquid to a constant volume, wherein the unit is mL;
V0volume of sample stock solution in mL.
5C, according to the operation steps, carrying out treatment on a vanadium energy storage medium sample B (V: 1.74mol/L, V)3+：0.88mol/L、SO4 2-: 4.35mol/L) is sampled for 30mL to detect, the absorbance is 0.263, and then the SO in the sample2The contents are as follows:
example 4
Precision experiment
The distillation device is assembled from right to left to SO2Adding 10mL of the prepared lead acetate solution into a receiving tube, opening an argon switch, adjusting the argon flow speed to 200mL/min, taking 60mL of vanadium energy storage medium (by using an injector) and injecting into a 250mL two-neck flask, measuring 70mL of three-level water by using a measuring cylinder, adding into the two-neck flask from an acid adding nitrogen introducing tube (or a bubbling tube), and bubbling for 10 min. After the bubbling is finished, lifting the lifting platform to enable the distillation flask to be placed in an oil bath pan with the temperature of 140 ℃ (the surface of the oil bath is covered by a paperboard in the heating process), and heating at constant temperature for 20 min. After the distillation is finished, the mixture is fed to SO2After 20.00mL of the iodine-saturated solution was added to the receiving tube, the whole volume was transferred to a 100mL brown volumetric flask, and 200. mu.L of concentrated hydrochloric acid was added to the brown volumetric flask to fix the volume. After 5min, detection was carried out at 287nm using a 1cm quartz cuvette. Respectively taking a vanadium energy storage medium sample C (V: 1.55mol/L, V)3+：0.78mol/L、SO4 2-: 4.08mol/L) and sample D (V: 1.60mol/L, V3+：0.79mol/L、SO4 2-: 4.20mol/L) were repeated 10 times, the relative standard deviation was calculated and the results are shown in table 1. The sulfur dioxide content detection precision experimental data of the vanadium energy storage medium samples (samples C and D) show that the detection resultsThe Relative Standard Deviation (RSD) is less than 5 percent, which shows that the detection result of the detection method has higher detection precision.
TABLE 1 precision test results
Example 5
The distillation device is assembled from right to left to SO2Adding 10mL of the prepared lead acetate solution into a receiving tube, opening an argon switch, adjusting the argon flow speed to 200mL/min, taking 60mL of the vanadium energy storage medium sample (by using an injector) and injecting into a 250mL two-neck flask, measuring 70mL of tertiary water by using a measuring cylinder, adding into the two-neck flask from an acid adding nitrogen introducing tube (or a bubbling tube), and bubbling for 10 min. After the bubbling is finished, Na is respectively removed by using a liquid-removing gun2SO30.1mL/0.2mL/0.3mL of standard solution and 0.5mL of tertiary water were added to the two-necked flask from an acid-nitrogen addition tube. Lifting the lifting platform to place the distillation flask in an oil bath pan at 140 deg.C (the oil bath surface is covered with paperboard during heating), and heating at constant temperature for 20 min. After the distillation is finished, the mixture is fed to SO2After 20.00mL of the iodine-saturated solution was added to the receiving tube, the whole volume was transferred to a 100mL brown volumetric flask, and 200. mu.L of concentrated hydrochloric acid was added to the brown volumetric flask to fix the volume. After 5min, detection was carried out at 287nm using a 1cm quartz cuvette. The recovery of the sample was calculated. The results are shown in Table 2. The recovery rate experiment result shows that the adding standard amount is in the range of 0.85-2.54mg/L, and the adding standard recovery rate is in the range of 88.2-102.0%, which indicates that the method has good detection accuracy in the concentration range and can be suitable for the production detection requirement.
TABLE 2 recovery rate test results
Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; while the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention.
Claims (8)
1. A method for measuring the content of sulfur dioxide in a vanadium energy storage medium by an ultraviolet-visible spectrophotometry is characterized by comprising the following steps:
step 1) standard working curve making
Transferring the series of volumes of sodium sulfite standard solutions into N brown containers filled with lead acetate solutions, respectively adding iodine saturated solutions into the N brown containers, and uniformly mixing, wherein N is more than or equal to 5; after reacting for 2-5min, adding a proper amount of concentrated hydrochloric acid to dissolve lead sulfate precipitate obtained by oxidizing lead sulfite and eliminate the influence of the precipitate on ultraviolet spectrophotometry detection; obtaining N samples to be detected by water constant volume, standing the samples to be detected for 3-5min, and measuring the solution absorbance values of the N samples to be detected at the characteristic spectral wavelength by using an ultraviolet-visible spectrophotometer, wherein the characteristic spectral wavelength is 287nm or 350nm, and SO contained in a series of volume sodium sulfite standard solutions is used2The content of (A) is an abscissa, and the absorbance is an ordinate to draw a standard working curve, so as to obtain a linear relation between the mass of the sulfur dioxide and the absorbance A; the volume ratio of the lead acetate solution to the iodine saturated solution is 1: 2-4;
step 2) determination of sulfur dioxide content in vanadium energy storage medium
Absorbing sulfur dioxide gas distilled from the vanadium energy storage medium by using a lead acetate solution; after distillation is carried out for 20-40min, adding iodine saturated solution into the lead acetate solution absorbing sulfur dioxide, and leading into a brown container after full reaction; adding a proper amount of concentrated hydrochloric acid into a brown container to dissolve lead sulfate precipitate obtained by oxidizing lead sulfite, eliminating the influence of the precipitate on ultraviolet spectrophotometry detection, and performing volume fixing with water to obtain a sample to be detected; standing the sample to be tested for 3-5min, sampling, and measuring the absorbance value of the sample to be tested at 287nm by using an ultraviolet-visible spectrophotometer; substituting the absorbance value into a linear equation of a standard working curve to calculate the mass of the sulfur dioxide, and dividing the numerical value by the sampling volume to obtain the content of the sulfur dioxide in the sample solution; the volume ratio of the lead acetate solution to the iodine saturated solution in the step 2) is the same as that in the step 1).
2. The method for measuring the sulfur dioxide content in the vanadium energy storage medium by using the ultraviolet-visible spectrophotometry as claimed in claim 1, wherein the concentration of the lead acetate solution is 1-2 g/L.
3. The method for measuring the sulfur dioxide content in the vanadium energy storage medium by using the ultraviolet-visible spectrophotometry as claimed in claim 1, wherein the iodine saturated solution is prepared by the following steps: weighing iodine solid, dissolving in absolute ethanol container, stirring to dissolve iodine completely, pouring ethanol solution of iodine into brown container containing three-stage water, dissolving with ultrasound, and standing for one day; filtering to obtain clear and transparent iodine solution; wherein the ratio of the mass of the iodine solid to the volume of the absolute ethyl alcohol to the volume of the tertiary water is 1-2 g: 10-20 mL: 1L of the compound.
4. The method for determining the sulfur dioxide content in the vanadium energy storage medium by using the ultraviolet-visible spectrophotometry method as claimed in claim 1, wherein the standard working curve in the step 1) needs to be calibrated before use, and the standard working curve needs to be prepared again when the iodine saturated solution is replaced.
5. The method for measuring the content of sulfur dioxide in a vanadium energy storage medium by using the ultraviolet-visible spectrophotometry method as claimed in claim 1, wherein the characteristic spectral wavelength of the solution in the step 1) or the step 2) is 287 nm.
6. The method for determining the content of sulfur dioxide in a vanadium energy storage medium by using the ultraviolet-visible spectrophotometry method according to claim 1, wherein the volume ratio of concentrated hydrochloric acid and a lead acetate solution added in the step 1) or the step 2) is 1:50-100, so that a lead sulfate precipitate obtained by oxidizing lead sulfite is dissolved, and the influence of the precipitate on the ultraviolet spectrophotometry detection is eliminated.
7. The method for measuring the sulfur dioxide content in the vanadium energy storage medium by using the ultraviolet-visible spectrophotometry as claimed in claim 1, wherein in the step 2), the distillation temperature is 120-160 ℃, and the distillation time is 20-40 min.
8. The method for measuring the sulfur dioxide content in the vanadium energy storage medium by using the ultraviolet-visible spectrophotometry as claimed in claim 1, wherein the step of absorbing the distilled sulfur dioxide gas by using the lead acetate solution comprises the following steps: introducing argon into an absorption container added with a lead acetate solution, injecting a vanadium energy storage medium into a distillation container at the argon flow rate of 150-.
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Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CA2465544A1 (en) * | 2001-11-02 | 2003-05-08 | Qmet Aps | A method of determining the content of so2 in a beverage product |
| CN103454233A (en) * | 2013-09-11 | 2013-12-18 | 浙江中一检测研究院股份有限公司 | Method for measuring sulfide in environment |
| CN104266986A (en) * | 2014-10-27 | 2015-01-07 | 合肥卓越分析仪器有限责任公司 | Method for detecting sulphur content in iron and steel sample |
| CN104977266A (en) * | 2015-04-24 | 2015-10-14 | 河北中医学院 | Apparatus and method for rapidly measuring sulfur dioxide residue level in Chinese herb |
| CN105021601A (en) * | 2015-06-24 | 2015-11-04 | 西南大学 | Food sulfur dioxide content determination method |
| CN106198846A (en) * | 2016-08-31 | 2016-12-07 | 大连博融新材料股份有限公司 | A kind of distillation absorbs chromatography of ions detection electrolyte sulfite radical content method |
| CN107110809A (en) * | 2014-11-10 | 2017-08-29 | 卡勒拉公司 | ion concentration measurement in the presence of organic matter |
-
2018
- 2018-01-17 CN CN201810042566.9A patent/CN108344702B/en active Active
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CA2465544A1 (en) * | 2001-11-02 | 2003-05-08 | Qmet Aps | A method of determining the content of so2 in a beverage product |
| CN103454233A (en) * | 2013-09-11 | 2013-12-18 | 浙江中一检测研究院股份有限公司 | Method for measuring sulfide in environment |
| CN104266986A (en) * | 2014-10-27 | 2015-01-07 | 合肥卓越分析仪器有限责任公司 | Method for detecting sulphur content in iron and steel sample |
| CN107110809A (en) * | 2014-11-10 | 2017-08-29 | 卡勒拉公司 | ion concentration measurement in the presence of organic matter |
| CN104977266A (en) * | 2015-04-24 | 2015-10-14 | 河北中医学院 | Apparatus and method for rapidly measuring sulfur dioxide residue level in Chinese herb |
| CN105021601A (en) * | 2015-06-24 | 2015-11-04 | 西南大学 | Food sulfur dioxide content determination method |
| CN106198846A (en) * | 2016-08-31 | 2016-12-07 | 大连博融新材料股份有限公司 | A kind of distillation absorbs chromatography of ions detection electrolyte sulfite radical content method |
Non-Patent Citations (1)
| Title |
|---|
| 淮山、党参等１０ 种中药材中二氧化硫残留量两种测定方法的比较;郑剑红;《海峡药学》;20121231;第24卷(第7期);第74-75页 * |
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